Sabo

Revolutionary Army chief of staff and Luffy's sworn brother.

Sabo is the chief of staff of the Revolutionary Army and the sworn brother of Monkey D. Luffy and Portgas D. Ace. Introduced as a noble from the Goa Kingdom years before the series' present, he leaves his home and family to live in the Gray Terminal.

Quick Facts

Affiliation: Revolutionary Army (chief of staff)
Origin: Noble of the Goa Kingdom
Devil fruit: Flame-Flame Fruit
Sworn brothers: Monkey D. Luffy, Portgas D. Ace
Japanese voice: Tōru Furuya (adult); Miyu Irino from episode 1116

Facts from the source article.

Background

After he and Ace befriend Luffy, the three exchange cups of sake and become "brothers". Sabo's ship is destroyed by a Celestial Dragon; though he is thought to have been killed, he survives and is rescued by Monkey D. Dragon, but suffers from amnesia. Under Dragon he joins the Revolutionary Army and rises through its ranks.

Hearing of Ace's death brings his memory back. Still loyal to the Revolutionary Army, Sabo sets out to obtain Ace's Devil Fruit, the Flame-Flame Fruit, to inherit Ace's will. He finds it as the prize of a tournament on Dressrosa, where he reunites with Luffy and takes his place using Luffy's alias "Lucy". After winning, he eats the fruit and battles Admiral Fujitora and Jesus Burgess to protect Luffy. He is later framed for the murder of Nefertari Cobra after witnessing the existence of Imu.